Draft gear



pm w, 1941. D. F. SPRQUL www@ DRAFT GEAR Filed Jan. l5, 1939 2Sheets-Sheet l Patentecl Apr. 15, 1941 DRAFT GEAR Donald F. Sproul,Chicago, Ill., ass'ignor to James R. Cardwell, Chicago, Ill.

Application January 13, 1939, Serial No. 250,673

Claims.

This invention relates to draft gears and to the method of making thesame.

One of the objects of the invention is the provision of a fabricateddraft gear having a maximum of strength with a minimum of weight.

Another object of the invention is the provision of a new and improvedmethod of constructing draft gear and of fabricating the parts.

A further object of the invention is the provision of a new and improvedwedging mechanism for use in draft gears of the friction type.

A still further object of the invention is the provision of a new andimproved draft gear built up from parts, sections or elements weldedtogether to form a rigid unitary structure.

Another object of the invention is the pro- Vision of a new and improveddraft gear that is simple in construction, easily fabricated, efficientin operation, andthat has maximum strength and minimum weight.

Other and further objects and. advantages of the invention will appearfrom the following description, taken in connection with theaccompanying drawings, in which,

Fig. 1 is a side elevation of the draft gear with the yoke in positionthereon;

Fig. 2 is a top plan view of the gear casing;

Fig. 3 is a horizontal section through the center sills of a. railwaycar with the gear in positionv therein;

Fig. 4 is a section on the line 4--4 of Fig. `3;

Fig. 5 is a section on the line 5 5 of Fig. 3;

Fig. 6 is a perspective view of the inner spring seat;

Fig. '7 is a perspective view of one of the inner wedge blocks orfriction shoes;

Fig. 8 is a perspective view of the outer spring seat; p

Fig. 9 is a perspective View of one of the outer wedge blocks orfriction shoes;

Fig. 101s a perspective View of the thrust member; and

Fig. 11 is a rear end view of the friction tubular member.

It will be noted that Figs. 6 to 10 designate an exploded view of aportion of the friction mechanism.

The trend in car building at the present time is toward cars of lighterweight per ton capacity; i. e. cars having a minimum deadweight. Inorder to accomplish this object, every part of the car has been goneover with a View to reducing the weight of the parts without sacrificingstrength or capacity. It is common practice to cast draft gear casingsbut in order to secure the proper Cil strength, the casing must be largeor massive with a resultant heavy and cumbersome structure.

The present invention seeks to remedy this difficulty by the provisionof a fabricated gear casing in which the casing is built up and rigidlywelded together thereby eliminating cast parts and greatly'reducing theweight of the gear.

Referring now to the drawings, the reference character Il] designates arailway car having the center sills II to which are attached the draftlugs I2 and the buffer lugs I3, Fig. 3. A draft gear I4 is adapted to bepositioned between the draft and buffer lugs, as shown more clearly inFig. 3 of the drawings. A follower plate I5 is inserted between thedraft lugs I2 and the buffer lugs I3.

The gear I4 comprises a housing or casing IB that is a fabricatedstructure. This housing comprises a length of pipe or a tubular memberor section I'I which in practice is a section of a tube of sufficientdiameter to form the casing The tube from which the housing is takenmaybe made inthe usual or any well known manner, and is of the seamlesstype.

Extending the full length of the tubular section I1, at each sidethereof, is a positioning or reinforcing angular member i3. This member,as shown, is in the form of a T-bar yhaving its stem portion I9extending radially from the tube at each side thereof and weldedthereto. Preferably, the stem I9 is welded at each side to the tubularmember, as shown at 2| and 22, Fig. 4. The flange portions 23 of theT-bar are in a vertical plane and are adapted to position the casingmidway between the center sills. These members also constitutereinforcing members for the casing.

A rectangular plate or follower 24 is rigidly connected to, what forconvenience of description will be termed, the front end of the casingas by being welded thereto. The plate is also rigidly connected to thepositioning or reinforcing bars I 8 as by being welded. thereto. Thecasing I1 is welded to the bar 24 on its inner and outer sides, as shownat 25 and 26 in Fig. 3. The weld at 25 being extremely difficult tomake, may be, and preferably is, omitted, in practice. A friction memberin the form of a tube 21 is pressed into the inner end of the casingI'l, Fig. 3, and this tubular member is welded as at 28 to the in nersurface of the casing.

An inner plate 20 extends across the rear end of the casing I1, Fig. 3,and is welded thereto. as at 29, in a manner similar to the plate 2li.The plate 24 also extends across the positioning T- bars I8 and iswelded to the bars by welds on each side of the bars in a manner alreadydescribed.

The plate is provided with an axial opening of substantially the samediameter as the exterior diameter of the member 21 and through which thetubular member 21 extends, as shown in Fig. 3. The tubular member iswelded at its outer side as at 3l throughout its circumference to theplate 29. The inner surface of the tubular member 21 is in the form ofthree segments of cylinder forming three friction surfaces 32a, 32h and32C converging inwardly for engaging the wedging mechanism, as willpresently appear. The plate 26 is in the form of an elongated octagonwith its major axis extending horizontally as shown in Fig. 5.

Suitable positioning reinforcing members 33' are provided at the endopposite the tubular member 21. These members, of which four areemployed, are roughly triangular in form, as shown more clearly in Fig,2, and have their outer or apex portions 34 extending horizontally andwith their inner or base portions 35 bent at an angle to the apexportion and extend radially of the casing to which they are attached asbeing welded thereon on opposite sides of the base portion. As shown,there are welds 36 and 31, Fig. 4, on each of the portions 35 of thepositioning members 33 for rigidly connecting the same to the casing.There are two positioning members 33 at the upper portion of the casingand two below. The outer portions of the positioning members 33 that areattached to the upper portion of the casing extend in oppositedirections in the same plane and likewise those secured to the lowerportions of the casing have their outer ends extending outwardly inopposite directions in the same plane. The members 33 are of such widthand are so arranged that they conform in outline to the length and widthof the plate 24, as shown in Fig. 4. Ihese members extend along thecasing to a plane adjacent to the inner end of the tubular member 21whereby the tubular member reinforces the inner end of the casing andthe members 33 reinforce the outer end. It will thus be seen that thecasing may be fabricated at a minimum of expense and will be muchstronger than the conventional casting.

Suitable wedging mechanism is provided for the casing. In the form ofthe construction shown, the wedging mechanism comprises what may betermed the outer wedge blocks or friction shoes 38 of which there arethree arranged substantially 120 apart, inner wedge blocks or frictionshoes 39 of which there are also three arranged the same distance apart.Each of the wedge blocks or shoes 38 has curved outer friction surfaces4I that frictionally engage the inclined friction surface 32 of thetubular member 21 and also have inner inclined wedging surfaces 42 andouter inclined wedging surfaces 43. The inner wedge blocks or frictionshoes 39 have outer curved friction surfaces 44 for engaging theinclined inner friction surfaces 32 of the tubular member 21 and arealso provided with an inner inclined wedge face 45 and an outer inclinedwedge face 46.

An outer spring seat 41 having inner inclined wedging faces 48 and outerinclined wedging faces 49 is positioned between the Wedge blocks 38 and39 and frictionally engages the same. That is, the friction faces 48 ofthe spring seat 41 engage the corresponding wedge faces 45 of 75 theinner wedge blocks 39 and likewise, the wedging, faces 49 of the springseat 41 engage the corresponding wedge faces 42 of the outer wedgeblocks 38. The spring seat 41 is hollow and as shown at 39 it has anaxial opening 40 through its rear wall and an axial opening 50 of largerdiameter through its front wall. An inner spring seat 5| having anenlarged axial opening is also provided. This spring seat has threeinclined wedging faces 52 for engaging the wedging faces 45 of the innerwedge blocks 39, respectively.

A thrust member 53 is provided for forcing the outer wedge block 38 intofrictional engagement with the tubular member 21. This member isprovided with three inclined wedging surfaces 54 that engage thecorresponding wedging faces 43 of the outer friction blocks 38,respectively. This member is provided with an inwardly extendingprojection 55 that extends through the opening 40 into the hollow 30 ofthe outer spring seat 41 as shown more clearly in Fig. 3 of thedrawings.

Suitable resilient means are provided for resisting the inward movementof the wedge blocks, spring seats and thrust member. In the form of theconstruction shown, three springs are employed. An inner spring 56engages the inner end of the projection 55 for resisting the inwardmovement of the thrust member 53 and for releasing the same when thecompressive force is released. An intermediate spring 51 is provided forengaging the outer wall of the spring seat 41 for resisting the inwardmovement of this seat upon the compression of the gear and for movingthe same outwardly upon the release of the gear. An outer spring 58 isalso provided for engaging the inner surface of the inner spring seat 5|and the spring also resists the inward movement of the inner spring seatupon the compression of the gear thereby causing the wedging surfaces toforce the Wedging blocks 39 into frictional contact with the innersurface of the tubular member 21.

The stem or projection 55 extends through the rear wall of the springseat 41 a sufficient distance to guide the thrust member and prevent itsskewing during compression of the gear. It is however, not extendedthrough the entire wedging and friction mechanism whereby the spring 56that seats against its forward end may be as long as possible therebyhaving greater capacity.

The friction surfaces of the tube 21 being inclined or tapered are inthe form of segments of a cylinder as indicated at 32a, 3219 and 32e inFigs. 5 and 11, whereby the shoes 38 and 39 are free to slide along thesurface thereof without b1nding or wedging. The friction surfaces 32a,32h and 32C converge inwardly and merge into the circular or cylindricalsurface of the interior (lifl the tubular member 21 as shown at 60 inFig.

It will thus be seen that upon compression of the gear, all of thesprings will cooperate to resist the inward movement of the wedgingmechanism thereby causing wedging action between the spring seats,friction blocks and thrust member for forcing the friction shoes orblocks 38 and 39 into frictional contact with the inner surface of .thetube 21. The inner surface of this tube being tapered inwardly causesincreasing wedging action with an increasing resistance to the imwardmovement of the wedging mechanism.

Suitable means are provided for holding the gear under initialcompression. As shown, a rod or bolt 6I having a head 62 and a threadedend 63 is employed for this purpose. The head 62 is seated in adepression 64 in a spring seat 65. The spring seat 65 engages theforward ends of the springs 56, l and 5B. The opposite or threaded endof the bolt or rod 6| extends through an axial opening in the extension55 of the thrust member and is provided with a nut 66 in a counterbore6l in said extension 55. When the gear is compressed, the nut movesoutward into a cavity 80 in the thrust member 53. This is considered animportant feature of the invention because the bolt 6I does not extendbeyond the gear even when the latter is compressed. In the conventionalgear having a bolt to hold the gear under initial compression, the bolt,when the gear is compressed, extends beyond the gear into the followerand is likely to get stuck or caught and hold the gear in its compressedcondition. A lead washer 68 is employed beneath the nut 66 wherel by thegear is held sufficiently compressed that it may be easily installed andafter being used a few times, the washer will flatten to permit the gearto expand to fill the pocket.

It is thought from the foregoing, taken in connection with theaccompanying drawings, that the operation and construction of my devicewill be apparent to those skilled in the art and that changes in size,shape, proportion or details may be made without departing from thespirit and scope of the appended claims.

I claim as my invention:

l. In a draft gear, a casing comprising a length of seamless tube, anangular bar extending along opposite sides and Welded to said casingalong each side of the bar, a front follower extending across theforward ends of said tube and bars and rigidly secured thereto by weldsat each side of the bars and along the inner and outer edge of saidtube, a rear plate extending across the rear ends of said bars and tubeand rigidly connected thereto, a friction tube pressed into the innerend of said seamless tube and extending beyond the end thereof, throughan axial opening in said plate and rigidly secured to said plate andseamless tube as by welding, and welds on opposite sides of each angularbar for securing the same to said plate.

2. In a built up draft gear, a casing comprising a length ofconventional seamless tubing of cir- D ly of said casing and weldedthereto at one end portion thereof, the horizontally extending portionsof one set being in a horizontal plane above said casing and those ofthe other set being in a horizontal plane below said casing, an endplate welded to said end of the casing and to all of said positioningmembers, and another end plate welded to the other end of said casingand to said T-shaped positioning members, one of said end plates onlyhaving an opening therethrough in alinement with that of said casing 3.A built up draft gear housing comprising a section of conventionalcylindrical seamless tube, a rectangular imperforate flat plate weldedto one end of said tube, a flat plate welded to the other end of saidtube and having a central opening therethrough, an open ended sleevepressed in said other end, said sleeve having its internal wall taperedoutwardly, and a reinforcing member of T-shape in cross sectionextending longitudinally of said tube at each opposite side thereofhaving its stem portion welded to said plates and tube whereby theflanges of said reinforcing members cooperate to serve as guides for thehousing.

4. A casing for a draft gear comprising a length of seamless tube, aplate secured to each end thereof as by welding, one of said platesbeing imperforate and the other having an axial opening of a diameterequal to that of the interior of said tube, a friction tube pressed intoone end of said seamless tube and extending through the opening in saidplate, positioning members generally triangular in form and each havingits apex portion extending laterally outwardly at an angle to its baseportion and with the base portion engaging said seamless tube andextending radially therefrom, Welds on the inner and outer sides of saidbase portion for securing the same to said seamless tube, and weldssecuring said base and apex portions to the adjacent plate, said apexportions extending along the top and bottom edges of the adjacent plateand flush therewith.

5. In a draft gear for railway cars, a casing comprising a length ofconventional seamless tube, a plate welded to each end thereof, one ofsaid plates being imperforate and the other having an axial opening inalinement with the bore of said tube, reinforcing bars extendinglongitudinally of said tube and welded thereto, said bars having theirends engaging said end plates and welded to said end plates, andsupporting bars welded to one end portion of said tube radially theretoand to the adjacent plate and having their outer portions turned inopposite directions in a common plane extending beneath said tube forsupporting said gear.

DONALD F. SPROUL.

